Battery cell, battery device, and electric device

Abstract

The application relates to the field of batteries, and provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises at least one electrode assembly, the electrode assembly comprises a diaphragm, two pole pieces with opposite polarities and an insulating layer. The two pole pieces and the diaphragm are wound and arranged, and the electrode assembly has a bending area. At least part of the insulating layer is arranged in the bending area and between the pole pieces and the diaphragm. The insulating layer comprises a base layer and a convex part, and the convex part is arranged on one side of the base layer along the thickness direction of the base layer. Based on the above structure, during winding and pre-pressing forming of the electrode assembly and during use of the battery monomer, the base layer can provide large-area support and buffering effect, so as to help uniformly disperse the bending stress and reduce local stress concentration of the pole pieces; the convex part can additionally reinforce the base layer, so as to enhance the resistance and carrying capacity of the bending stress and reduce the bending stress borne by the bending part of the pole pieces; and thus the risk of cracking and other phenomena of the bending part of the pole pieces can be reduced.

Description

Technical Field

[0001] This application belongs to the field of battery technology, and in particular relates to a battery cell, a battery device, and an electrical device. Background Technology

[0002] Electrode assemblies are essential components for electrochemical reactions to occur in a single battery cell. An electrode assembly includes two electrodes of opposite polarity and a separator separating the two electrodes. The two electrodes and the separator are wound together and subjected to subsequent processes such as compaction to form the electrode assembly, which thus has a main body region and bending regions disposed at the ends of the main body region.

[0003] However, during the winding and pre-pressing of the electrode assembly and during the use of the battery cell, the portion of the electrode corresponding to the bending area will be subjected to greater stress due to bending, which may cause cracking, loss of active material, and burrs in the portion of the electrode corresponding to the bending area. Summary of the Invention

[0004] This application provides a battery cell, a battery device, and an electrical device, aiming to solve the problem that the portion of the electrode sheet corresponding to the bending area in the electrode assembly is prone to cracking.

[0005] To achieve the above objectives, the technical solution adopted in the embodiments of this application is as follows:

[0006] In one aspect, a battery cell is provided, the battery cell including at least one electrode assembly, the electrode assembly including a separator, two electrodes of opposite polarity, and an insulating layer;

[0007] The electrode assembly has a bending zone with two electrodes and a diaphragm wound together.

[0008] At least a portion of the insulating layer is disposed in the bending area and between the electrode and the diaphragm;

[0009] The insulating layer includes a base layer and a protrusion, with the protrusion located on one side of the base layer along its own thickness direction.

[0010] The battery cell provided in this application provides a supporting and buffering effect on the bent portion of the electrode sheet by providing an insulating layer between the bent portion of the electrode sheet (i.e., the portion of the electrode sheet corresponding to the bent area) and the separator, and the insulating layer includes a substrate layer and protrusions protruding from the substrate layer. During the winding and pre-pressing of the electrode assembly (not limited to hot pressing or cold pressing) and during the use of the battery cell, the insulating layer provides a supporting and buffering effect on the bent portion of the electrode sheet. In particular, the supporting and buffering effect is provided over a large area through the substrate layer to help evenly distribute bending stress and reduce local stress concentration of the electrode sheet. In particular, the protrusions further strengthen the substrate layer to enhance the resistance and load-bearing capacity to bending stress, thereby reducing the bending stress borne by the bent portion of the electrode sheet. Based on the supporting and reinforcing effect of the aforementioned insulating layer, the risk of cracking and active material shedding in the bent portion of the electrode sheet can be effectively reduced. This reduces the risk of reduced active material content in the bent portion of the electrode sheet during electrode assembly winding and pre-pressing, as well as during the use of the battery cell. Consequently, it reduces the risk of metal precipitation in the bent portion of the electrode sheet due to reduced active material during the use of the battery cell, alleviates metal precipitation in the bent area, slows dendrite growth, and improves the reliability and lifespan of the battery cell. Furthermore, it reduces the risk of reduced energy density due to reduced active material, thus maintaining the energy density and electrochemical performance of the battery cell.

[0011] Based on the supporting and reinforcing effect of the above-mentioned insulating layer, the risk of burrs and other phenomena in the bent part of the electrode sheet can be effectively reduced. Moreover, even if burrs are generated in the bent part of the electrode sheet, the insulating layer can block the burrs to effectively prevent them from piercing the separator, thereby reducing the risk of internal short circuits in the battery cell and improving the reliability and service life of the battery cell.

[0012] Furthermore, during the winding and pre-pressing of the electrode assembly, the insulating layer can also, based on the substrate layer and protrusions, promote the compaction of the bent portion of the electrode and reduce the material gaps, thereby improving the compaction of the electrode (i.e., the density after compaction), which is beneficial to improving the energy density and electrochemical performance of the battery cell.

[0013] In some embodiments, the substrate layer has a middle portion located in the middle of the bending region along the winding direction, and the protrusions are disposed away from the middle portion.

[0014] By adopting the above solution, the rigidity of the protrusions on the intermediate portion can be reduced, allowing the intermediate portion to have better flexibility and enabling it to bend freely and smoothly. This reduces the bending resistance of the intermediate portion. Based on this, during the winding and pre-pressing of the electrode assembly, the insulating layer can bend smoothly along with the electrode and separator through the intermediate portion, and share the bending stress in the area corresponding to the intermediate portion of the electrode. Furthermore, the protrusions can provide additional support and buffering in areas outside the intermediate portion to disperse bending stress and reduce stress concentration in the intermediate portion. Therefore, the risk of cracking, active material shedding, and burr formation in the bent portion of the electrode can be reduced, especially in the area corresponding to the intermediate portion of the electrode.

[0015] In some embodiments, the insulating layer has a plurality of protrusions, which are located on opposite sides of the middle portion along the winding direction.

[0016] By adopting the above scheme, the insulating layer can provide support and buffering on both sides of the middle part through multiple protrusions, and distribute and disperse the bending stress relatively evenly on both sides of the middle part. This can relatively evenly optimize the resistance and load-bearing capacity of each area of ​​the insulating layer to bending stress, thereby relatively evenly reducing the bending stress borne by each area of ​​the bent part of the electrode sheet during the winding and pre-pressing of the electrode assembly and during the use of the battery cell. This reduces the stress concentration in the bent part of the electrode sheet and lowers the risk of cracking, active material shedding, burr formation, and other phenomena in the bent part of the electrode sheet.

[0017] In some embodiments, along the thickness direction of the electrode assembly, the projections of all protrusions of the same insulating layer do not overlap at all.

[0018] By adopting the above scheme, and by ensuring that the projections of all protrusions of the same insulating layer along the thickness direction of the electrode assembly do not overlap, in a tightly wound electrode assembly, on any reference line that "passes through the protrusion" and "is parallel to the thickness direction of the electrode assembly", the "chord length of the electrode relative to the outer side of the insulating layer in two adjacent electrodes" is increased by a length L0 compared to the "chord length of the electrode relative to the inner side of the insulating layer in two adjacent electrodes". L0 is the sum of the thickness of the two base layers and the thickness of one protrusion. When the projections of the protrusions of the same insulating layer along the thickness direction of the electrode assembly overlap, the aforementioned L0 is the sum of the thickness of the two base layers and the thickness of the two protrusions. Therefore, based on the configuration of this embodiment, the increase in the "radius of curvature of the electrode located on the outer side of the insulating layer among two adjacent electrodes" compared to the "radius of curvature of the electrode located on the inner side of the insulating layer among two adjacent electrodes" is smaller. This results in a smaller increase in the average gap between the bent portions of two adjacent electrodes, thereby reducing the risk of a large increase in the active ion transport distance due to a large increase in the average gap between the bent portions of two adjacent electrodes. It also reduces the risk of exacerbating metal precipitation due to a large increase in the active ion transport distance, thus alleviating metal precipitation in the bent area, reducing dendrite growth rate, and improving the reliability and service life of the battery cell.

[0019] In some embodiments, the protrusion is a strip-shaped structure.

[0020] By adopting the above scheme, and making the protrusions into strip-shaped structures, the protrusions can provide continuous support and buffering effects along their extension direction. This facilitates the continuous and uniform distribution of bending stress along the extension direction, reducing local stress concentration. Consequently, it enhances the overall resistance and load-bearing capacity of the insulation layer to bending stress, reduces the bending stress borne by the bent portion of the electrode, and lowers the risk of cracking, active material shedding, and burr formation in the bent portion of the electrode. Furthermore, during the winding and pre-pressing of the electrode assembly, the strip-shaped protrusions can create uniform contact pressure between the electrode and the separator. This promotes relatively uniform and tight compaction of the components in the bent portion of the electrode, reduces material gaps, and evenly improves the electrode compaction, thereby enhancing the energy density and electrochemical performance of the battery cell.

[0021] In some embodiments, the extension direction of the protrusion is parallel to the length direction of the substrate layer.

[0022] By adopting the above scheme, and making the extension direction of the protrusion parallel to the length direction of the substrate layer, the extension direction of the protrusion can be made to conform to the extension direction and winding direction of the electrode or separator attached to the substrate layer. This allows the protrusion to have a longer extension length, facilitating the alternating arrangement of a large number of protrusions along the width direction of the substrate layer. Based on this, during the winding and pre-pressing of the electrode assembly and during the use of the battery cell, the protrusion can provide continuous and reliable support and buffering along the extension and winding direction of the electrode, effectively bearing bending stress and distributing it more evenly. This enhances the overall resistance and load-bearing capacity of the insulation layer to bending stress, reduces the bending stress borne by the bent portion of the electrode, and lowers the risk of cracking, active material shedding, and burr formation in the bent portion of the electrode. This embodiment is particularly suitable for situations where the substrate layer is long, fully utilizing the extension length of the protrusion to better bear bending stress.

[0023] In some embodiments, the extension direction of the protrusion is perpendicular to the length direction of the substrate layer.

[0024] By adopting the above scheme, and making the extension direction of the protrusions perpendicular to the length direction of the substrate layer, the extension direction of the protrusions can be perpendicular to the extension direction and winding direction of the electrode or separator attached to the substrate layer, while conforming to the width direction of the substrate layer and the width direction of the electrode. This facilitates the alternating arrangement of a small number of protrusions with a relatively concentrated layout along the length direction of the substrate layer. Based on this, during the winding and pre-pressing of the electrode assembly and during the use of the battery cell, the protrusions can provide strong local support and buffering in the bending area along the width direction of the electrode, focusing on bearing bending stress in the bending area and reducing stress concentration. This helps to enhance the overall resistance and load-bearing capacity of the insulation layer to bending stress, reduce the bending stress borne by the bent part of the electrode, and reduce the risk of cracking, active material shedding, and burr formation in the bent part of the electrode. This embodiment is particularly suitable for situations where the "substrate layer is relatively short," as it can concentrate the protrusions within the limited length of the substrate layer to provide effective local support and better bear bending stress.

[0025] In some embodiments, the insulating layer has a plurality of protrusions, which are arranged in parallel and spaced apart.

[0026] By adopting the above scheme, and by setting multiple parallel and spaced protrusions on the insulation layer, the multiple protrusions can work together in the bending area to provide multi-area and large-scale support and buffering. They share the bending stress along the same extension direction and evenly distribute the bending stress, effectively reducing local stress concentration. This helps to evenly improve the resistance and load-bearing capacity of each area of ​​the insulation layer to bending stress, reduce the bending stress borne by the bent part of the electrode, and reduce the risk of cracking, active material shedding, and burr formation in the bent part of the electrode.

[0027] In some embodiments, the substrate layer restricts the free penetration of active ions, and the substrate layer has a perforated structure along its thickness direction, with the perforated structure avoiding protrusions along the thickness direction of the substrate layer.

[0028] By adopting the above scheme, in situations where the substrate layer restricts the free penetration of active ions, a perforated structure is created along the thickness direction of the substrate layer. This perforated structure facilitates the formation of transport channels for electrolyte, active ions, and electrons, allowing active ions to penetrate freely and improving ion transport efficiency. Based on this, the active material in the portion of the electrode corresponding to the perforated structure can function normally and participate in electrochemical reactions. This reduces the obstruction of the insulating layer by the active material, minimizing its loss and waste, improving its utilization rate, and enhancing the capacity, energy density, and electrochemical performance of the battery cell. Furthermore, by ensuring the perforated structure avoids protrusions along the thickness direction of the substrate layer, the structural integrity of the protrusions is maintained, allowing them to effectively reinforce the substrate layer. This effectively enhances the substrate layer's resistance to bending stress and its load-bearing capacity, and effectively reduces stress concentration at bending points of the electrode.

[0029] In some embodiments, the substrate layer includes a border portion and a middle portion, the middle portion being disposed within the enclosed area of ​​the border portion and located in the middle of the bending area along the winding direction, and the hollow structure being disposed away from the border portion and the middle portion.

[0030] By adopting the above scheme, based on the formation of transport channels for electrolyte, active ions, and electrons through the hollow structure, and by setting the hollow structure to avoid the edge and middle portions, the structural integrity of the key support areas of the substrate layer (i.e., the edge and middle portions) can be maintained. Therefore, the complete edge portion can easily provide structural support and mechanical strength to the entire substrate layer, and the complete middle portion can easily maintain the strength and flexibility of the central area of ​​the substrate layer. This allows the edge and middle portions to jointly form a high-strength support frame for the substrate layer, enabling the substrate layer to bend freely and flexibly during winding, pre-pressing, and use. It can better resist and disperse bending stress, reduce stress concentration in the bent portions of the electrode, and lower the risk of cracking, active material shedding, and burr formation in the bent portions of the electrode. Furthermore, maintaining the structural integrity of the edge portion also facilitates the thorough and reliable installation and fixation of the insulation layer through the edge portion in subsequent embodiments.

[0031] In some embodiments, the substrate layer allows active ions to penetrate freely.

[0032] By adopting the above scheme, allowing active ions to freely penetrate the substrate layer, the substrate layer itself possesses active ion transport channels, enabling free penetration of active ions. Based on this, the active materials corresponding to the substrate layer of the electrode can function normally and participate in electrochemical reactions, thereby reducing the obstruction of the insulating layer on the active materials, minimizing the sacrifice and waste of active materials, improving the utilization rate of active materials, and enhancing the capacity, energy density, and electrochemical performance of the battery cell. Furthermore, the substrate layer does not require a hollow structure to provide transport channels for active ions, thus simplifying its structure, reducing processing difficulty and steps, and facilitating the processing and forming of the substrate layer and insulating layer. It also improves the structural integrity, overall integrity, and mechanical properties of the substrate layer, allowing it to better resist and disperse bending stress during winding, pre-pressing, and use, reducing stress concentration in the bent portions of the electrode, and lowering the risk of cracking, active material shedding, and burr formation in the bent portions of the electrode.

[0033] In some embodiments, the electrode assembly includes an insulating adhesive layer, and the side of the substrate layer facing away from the protrusion is bonded to the electrode or diaphragm by the insulating adhesive layer, and the insulating adhesive layer is disposed along the thickness direction of the substrate layer to avoid the hollow structure.

[0034] By adopting the above solution, the side of the substrate layer facing away from the protrusion can be bonded and fixed to the electrode or diaphragm through the insulating adhesive layer, so as to conveniently and quickly realize the installation and fixation of the insulating layer. This can conveniently, quickly and reliably stabilize the position and state of the insulating layer between the electrode and the diaphragm, enhance the overall structural stability of the electrode assembly, enable the insulating layer to be permanently and reliably stable between the electrode and the diaphragm, and better resist and disperse bending stress during winding, pre-pressing and use. Furthermore, by ensuring the substrate layer has a perforated structure, the insulating adhesive layer can be positioned along the thickness direction of the substrate layer to avoid the perforated structure. This prevents the insulating adhesive layer from blocking or clogging the transmission channels formed by the perforated structure, thereby reducing the impact of the insulating adhesive layer on the charging and discharging process of the electrode assembly and battery cells. This allows the perforated structure to function properly as a transmission channel, enabling electrolyte, active ions, and electrons to pass through freely. It also allows the active materials in the corresponding perforated parts of the electrode to function properly and participate in electrochemical reactions, thereby improving the utilization rate of active materials and the active ion transport rate, and enhancing the capacity, energy density, and electrochemical performance of the battery cells.

[0035] In some embodiments, the electrode assembly includes an insulating adhesive layer, and the side of the substrate layer facing away from the protrusion is bonded to the electrode or diaphragm through the insulating adhesive layer. Along the thickness direction of the substrate layer, the projected area of ​​the insulating adhesive layer is smaller than the projected area of ​​the substrate layer.

[0036] By adopting the above scheme, the side of the substrate layer facing away from the convex part can be bonded and fixed to the electrode or separator through the insulating adhesive layer. This facilitates the convenient and quick installation and fixation of the insulating layer, thereby conveniently, quickly, and reliably stabilizing the position and state of the insulating layer between the electrode and separator. This enhances the overall structural stability of the electrode assembly and ensures that the insulating layer is permanently and reliably stable between the electrode and separator. Furthermore, it effectively resists and disperses bending stress during winding, pre-pressing, and use. Moreover, while allowing active ions to freely penetrate the substrate layer, by making the projected area of ​​the insulating adhesive layer smaller than that of the substrate layer, the insulating adhesive layer does not completely block or obstruct the transport channels inherent in the substrate layer itself. This reduces the impact of the insulating adhesive layer on the charging and discharging process of the electrode assembly and individual battery cells. It allows areas of the substrate layer without the insulating adhesive layer to normally provide transport channels, enabling active ions to freely penetrate. This improves the utilization rate of active materials and the active ion transport rate, thereby enhancing the capacity, energy density, and electrochemical performance of the individual battery cells.

[0037] In some embodiments, the substrate layer is adhesive, and the side of the substrate layer opposite to the protrusion is bonded to the electrode or diaphragm.

[0038] By adopting the above solution, the substrate layer can be bonded to the electrode or diaphragm conveniently, quickly, and reliably by increasing the content of the adhesive to make the side facing away from the protrusion have sufficient adhesion. Based on this, the installation and fixation of the insulation layer can be achieved conveniently and quickly, thereby stabilizing the position and state of the insulation layer between the electrode and the diaphragm conveniently, quickly, and reliably. This can enhance the overall structural stability of the electrode assembly, enable the insulation layer to be permanently and reliably fixed between the electrode and the diaphragm, and better resist and disperse bending stress during winding, pre-pressing, and use.

[0039] In some embodiments, the side of the substrate layer facing away from the protrusion is bonded to the electrode or diaphragm by a solvent adhesive soluble in the electrolyte.

[0040] By adopting the above solution, before the electrode assembly is wound and formed, the side of the substrate layer facing away from the protrusion can be bonded to the preset position of the electrode or separator using a solvent adhesive, so as to stabilize the preset position and preset state relative to the electrode or separator. Based on this, during the winding and pre-pressing of the electrode assembly, the insulating layer can be wound along with the electrode or separator in a stable position and state relative to the electrode or separator, and is wound into the bending area. This allows for convenient and quick installation and fixation of the insulating layer, convenient, quick and reliable stabilization of the position and state of the insulating layer between the electrode and separator, enhances the overall structural stability of the electrode assembly, enables the insulating layer to be permanently and reliably fixed between the electrode and separator, and can better resist and disperse bending stress during winding, pre-pressing and use.

[0041] In some embodiments, the electrolyte contains a solvent gel.

[0042] By adopting the above scheme, when the electrode assembly and electrolyte are installed inside the battery cell, the solvent can be at least partially dissolved in the electrolyte to reduce or even eliminate the obstruction of the insulating layer. This allows a transmission channel to be left between the insulating layer and the electrode or separator, enabling active ions to penetrate freely. This reduces the impact of the solvent on the charging and discharging process of the electrode assembly and battery cell, improves the utilization rate of active materials and the active ion transport rate, and enhances the capacity, energy density and electrochemical performance of the battery cell.

[0043] In some embodiments, the electrode assembly includes a conductive adhesive layer, and the side of the substrate layer facing away from the protrusion is bonded to the electrode or diaphragm via the conductive adhesive layer.

[0044] By adopting the above-mentioned scheme, the adhesive layer's adhesion and electrolyte resistance properties allow the substrate layer to be bonded and fixed to the electrode or separator on the side opposite to the protrusion using the conductive adhesive layer. This facilitates the convenient and quick installation and fixation of the insulating layer, thereby ensuring a stable position and state of the insulating layer between the electrode and separator. This enhances the overall structural stability of the electrode assembly, ensuring the insulating layer remains reliably and permanently fixed between the electrode and separator. Furthermore, it effectively resists and disperses bending stress during winding, pre-pressing, and use. Moreover, the conductivity of the conductive adhesive layer itself provides transport channels, allowing active ions to freely penetrate. This reduces the impact of the conductive adhesive layer on the charging and discharging process of the electrode assembly and individual battery cells. It also facilitates the creation of transport channels between the insulating layer and the electrode or separator, improving the utilization rate of active materials and the active ion transport rate, ultimately enhancing the capacity, energy density, and electrochemical performance of the individual battery cells.

[0045] In some embodiments, the thickness of the protrusion is 1 to 3 times the thickness of the substrate layer along the thickness direction of the substrate layer.

[0046] By adopting the above-mentioned scheme, the thickness of the protrusion along the thickness direction of the substrate layer can be made moderate, without being excessive. Based on this, on the one hand, the protrusion can more effectively bear and disperse bending stress, thereby enhancing the overall resistance and load-bearing capacity of the insulation layer to bending stress, reducing the bending stress borne by the bent portion of the electrode, and mitigating the risk of cracking, active material shedding, and burr formation in the bent portion of the electrode. On the other hand, it reduces the risk of a large average gap between the bent portions of adjacent electrodes due to excessive protrusion thickness, thus reducing the risk of a large active ion transport distance and the risk of increased metal precipitation due to a large active ion transport distance. This alleviates metal precipitation in the bending area, slows dendrite growth, and improves the reliability and lifespan of the battery cell.

[0047] In some embodiments, the insulating layer is disposed on the convex or concave side of the first to third turns of the electrode from the inside out.

[0048] By adopting the above solution, and placing the insulating layer on the convex or concave side of the first to third turns of the electrode from the inside out, the insulating layer can primarily help the bent portions of the first to third turns of the electrode to bear and disperse bending stress, thereby significantly reducing the risk of cracking, active material shedding, and burr formation in these bent portions. Furthermore, since the risk of cracking and active material shedding in the bent portions of the first to third turns of the electrode from the inside out is primarily reduced, the risk of reduced active material content in these bent portions is also significantly reduced. Therefore, during the use of the battery cell, the risk of accelerated metal precipitation in the bent portions of the first to third turns of the electrode from the inside out is significantly reduced, effectively mitigating metal precipitation in the bending area and reducing dendrite growth rate, thus effectively improving the reliability and lifespan of the battery cell.

[0049] Secondly, a battery device is provided, which includes the battery cell provided in the embodiments of this application.

[0050] By adopting the above solution, the battery device can improve its charge-discharge performance, cycle performance, and reliability by using the battery cells provided in the embodiments of this application, and extend the service life of the battery device.

[0051] Thirdly, an electrical device is provided, which includes the battery device provided in the embodiments of this application, or the battery cell provided in the embodiments of this application.

[0052] By adopting the above-described solution, the performance, reliability, and service life of the electrical device can be improved by applying the battery device or battery cell provided in the embodiments of this application. Attached Figure Description

[0053] To clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments of this application or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0055] Figure 2 This is an exploded view of a battery device provided in some embodiments of this application;

[0056] Figure 3 This is an exploded view of a battery cell provided in some embodiments of this application;

[0057] Figure 4 This is a schematic diagram of the structure of an electrode assembly provided in some embodiments of this application;

[0058] Figure 5 for Figure 4 A partial schematic diagram of the provided electrode assembly shows that the side of the substrate layer facing away from the protrusion is bonded to the electrode sheet through an insulating adhesive layer;

[0059] Figure 6 A front view of an insulating layer in an unfolded state provided in some embodiments of this application, wherein the extending direction of the protrusion is perpendicular to the length direction of the base layer;

[0060] Figure 7 for Figure 6 A side view of the provided insulation layer;

[0061] Figure 8 The following is a front view of the insulating layer in an unfolded state according to some other embodiments of this application, wherein the extension direction of the protrusion is perpendicular to the length direction of the base layer, and the base layer has a through-hole structure.

[0062] Figure 9 A front view of an insulating layer in an unfolded state provided in some other embodiments of this application, wherein the extending direction of the protrusion is parallel to the length direction of the base layer;

[0063] Figure 10 The following is a front view of the insulating layer in an unfolded state according to some other embodiments of this application, wherein the extension direction of the protrusion is parallel to the length direction of the base layer, and the base layer has a through-hole structure.

[0064] Figure 11 This is a partial schematic diagram of an electrode assembly provided in some other embodiments of this application, wherein the substrate layer is bonded to the electrode sheet on the side opposite to the protrusion;

[0065] Figure 12 This is a schematic diagram of the structure of the insulating layer and solvent provided in some embodiments of this application;

[0066] Figure 13 This is a partial schematic diagram of an electrode assembly provided in some other embodiments of this application, wherein the side of the substrate layer facing away from the protrusion is bonded to the electrode sheet by a conductive adhesive layer.

[0067] The following are the labeling elements in the figure:

[0068] 1-Battery assembly, 2-Controller, 3-Motor; 100-Battery cell, 200-Casing, 201-First part, 202-Second part; 10-Battery cell, 11-Casing, 111-Shell, 112-End cap; 12-Electrode assembly, 121-Electrode body, 122-Taper, 122a-Positive electrode tab, 122b-Negative electrode tab; 13-Insulator; 14-Electrode terminal, 14a-Positive electrode terminal, 14b-Negative electrode terminal; 15-Adapter, 15a-Positive adapter, 15b-Negative adapter; 16-Pressure relief mechanism; 123-Separator, 124-Electrode sheet, 124a-Positive electrode sheet, 1 24b - Negative electrode sheet, 125 - Insulating layer, 1251 - Substrate layer, 12511 - Middle part, 12512 - Frame part, 12513 - Hollow structure, 1252 - Protrusion, 1252a - First protrusion, 1252b - Second protrusion, 126 - Bending area, 127 - Main body area, 128 - Insulating adhesive layer, 129 - Solvent, 1210 - Conductive adhesive layer, z - Thickness direction of substrate layer, x - Length direction of substrate layer, y - Width direction of substrate layer, a - Thickness direction of electrode assembly, b - Winding direction, d1 - Thickness of protrusion, d2 - Thickness of substrate layer, L1 - First reference line, L2 - Second reference line. Detailed Implementation

[0069] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clear, the application will be described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application. Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions. Unless otherwise specified, all technical features and optional technical features of this application can be combined to form new technical solutions.

[0070] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0071] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0072] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0073] A battery cell is the smallest unit for storing and outputting electrical energy. A battery cell typically contains at least one electrode assembly. The electrode assembly is an essential component for electrochemical reactions to occur within the battery cell. The electrode assembly includes two electrodes of opposite polarity (i.e., a positive electrode and a negative electrode), and a separator separating the two electrodes. The two electrodes and the separator are wound together and subjected to subsequent processes such as compaction to form a flat, rolled electrode assembly, resulting in a main body region and bending regions located at the ends of the main body region.

[0074] However, during the winding and pre-pressing of the electrode assembly and during the use of the battery cell, the portion of the electrode corresponding to the bending area will be subjected to greater stress due to bending. The inner circle has a smaller radius of curvature and a greater stress, which may cause cracking, loss of active material, and burrs in the portion of the electrode corresponding to the bending area.

[0075] Furthermore, during the use of a single battery cell, metal deposition may occur in the bending area. Metal deposition refers to the phenomenon where, during the charging process of a single battery cell, active ions cannot be inserted into the negative electrode active material in time and are reduced on the negative electrode surface, resulting in metal deposition. If, during the winding and pre-pressing of the electrode assembly and during the use of the single battery cell, the portion of the negative electrode corresponding to the bending area experiences cracking, loss of active material, or other phenomena that reduce the content of active material, more active ions may fail to insert into the negative electrode active material and precipitate out, exacerbating the metal deposition phenomenon. As the amount of deposited metal accumulates, the deposited metal is prone to forming dendrites. These dendrites may pierce the separator, conduct electricity between the positive and negative electrode sheets, and cause an internal short circuit within the battery cell.

[0076] Therefore, some embodiments of this application provide a battery cell that, by providing an insulating layer between the bent portion of the electrode and the separator, and by having the insulating layer include a substrate layer and protrusions protruding from the substrate layer, provides support and cushioning for the bent portion of the electrode during electrode assembly winding and pre-forming, as well as during the use of the battery cell; in particular, it provides support and cushioning over a large area of ​​the substrate layer to help evenly distribute bending stress and reduce local stress concentration in the electrode; and in particular, it further strengthens the substrate layer through the protrusions to enhance resistance and load-bearing capacity to bending stress, thereby reducing the bending stress borne by the bent portion of the electrode. Based on the supporting and reinforcing effects of the insulating layer, the risk of cracking and active material shedding at the bending points of the electrode sheet can be effectively reduced. This reduces the risk of decreased active material content at the bending points of the electrode sheet during electrode assembly winding and pre-pressing, as well as during the use of the battery cell. Furthermore, it mitigates the risk of accelerated metal precipitation at the bending points due to reduced active material, thus reducing dendrite growth and improving the reliability and lifespan of the battery cell. Additionally, it reduces the risk of decreased energy density due to reduced active material, maintaining the energy density and electrochemical performance of the battery cell. The insulating layer also effectively reduces the risk of burrs at the bending points of the electrode sheet. Even if burrs do form, the insulating layer blocks them, preventing them from piercing the separator and reducing the risk of internal short circuits in the battery cell, further improving its reliability and lifespan. Furthermore, during the winding and pre-pressing of the electrode assembly, the insulating layer can also, based on the substrate layer and protrusions, promote the compaction of the bent portion of the electrode and reduce the material gaps, thereby improving the compaction of the electrode (i.e., the density after compaction), which is beneficial to improving the energy density and electrochemical performance of the battery cell.

[0077] The battery cells disclosed in this application can be used independently or combined with other battery cells to form modular battery devices that can provide higher voltage and capacity, such as battery modules, battery packs, or battery stacks. The battery cells and battery devices disclosed in this application can be used in electrical devices that use the battery cells and battery devices as a power source, or in various energy storage systems that use the battery cells and battery devices as energy storage elements. Electrical devices can be, but are not limited to, vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered vehicles, natural gas-powered vehicles, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.

[0078] To illustrate the technical solution provided in this application, the following detailed description is provided in conjunction with specific drawings and embodiments, taking "an electrical device as a vehicle" as an example.

[0079] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle provided in some embodiments of this application. The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 1 is installed inside the vehicle, and the battery device 1 can be located at the bottom, front, or rear of the vehicle. The battery device 1 is used to supply power to the vehicle; for example, the battery device 1 can serve as the vehicle's operating power source. The vehicle may also include a controller 2 and a motor 3. The controller 2 is used to control the battery device 1 to supply power to the motor 3, for example, to meet the power needs of the vehicle during starting, navigation, and driving.

[0080] In some embodiments of this application, the battery device 1 can not only serve as the operating power source for the vehicle, but also as the driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0081] Please see Figure 2 , Figure 2 This is an exploded view of a battery device 1 provided in some embodiments of this application. The battery device 1 includes a battery cell 100 and a housing 200, with the battery cell 100 housed within the housing 200.

[0082] The housing 200 provides a space for the battery unit 100 and other components. The housing 200 can protect the battery unit 100 and other components inside from dust, water, and dirt, and can reduce the impact of external liquids or other foreign objects on the effectiveness and performance of the battery unit 100 and other components, and can effectively extend the service life of the battery device 1.

[0083] The housing 200 can adopt various structures. In some embodiments, the housing 200 may include a first portion 201 and a second portion 202, which overlap each other, and together define a receiving space for accommodating the battery unit 100. The second portion 202 may be a hollow structure with one end open, and the first portion 201 may be a plate-like structure, with the first portion 201 covering the open side of the second portion 202 so that the first portion 201 and the second portion 202 together define the receiving space; the first portion 201 and the second portion 202 may also be hollow structures with one side open, with the open side of the first portion 201 covering the open side of the second portion 202.

[0084] The box 200 can be of various shapes, such as a cylinder or a cuboid.

[0085] The enclosure 200 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0086] Battery cell 100 is an energy storage unit capable of converting chemical energy into electrical energy. In battery device 1, one battery cell 100 may be provided, or at least two battery cells 100 may be provided. When at least two battery cells 100 are provided, the at least two battery cells 100 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that at least two battery cells 100 are connected in both series and parallel.

[0087] The battery unit 100 may include at least two individual battery cells. These at least two individual battery cells may be directly connected in series, parallel, or a combination thereof, and then the entire assembly of the at least two individual battery cells is housed within the casing 200. The individual battery cells may be lithium-ion rechargeable battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells, or magnesium-ion battery cells, etc. The individual battery cells may be cylindrical, flat, cuboid, or other shapes, etc. Different packaging methods may be used to form cylindrical battery cells, square battery cells, or pouch battery cells, etc.

[0088] Alternatively, the battery cell 100 can be a battery module or battery assembly. That is, at least two battery cells can be connected in series, parallel, or in a hybrid configuration to form a modular structure (i.e., a battery module or battery assembly); at least two battery modules or battery assemblies can then be connected in series, parallel, or in a hybrid configuration to form a whole, which is housed within the housing 200.

[0089] Of course, the battery device 1 may also include other structures. For example, the battery device 1 may also include a busbar (not shown) for realizing electrical connection between at least two battery cells 100. As another example, the battery device 1 may also include a power distribution device (not shown) for acting as a control unit for distributing the energy of the battery device 1 and for distributing high voltage to the battery device 1.

[0090] Of course, in some embodiments, the battery device 1 may not include the housing 200, but instead, at least two battery cells are electrically connected and assembled into an integral whole by necessary fixing structures (such as end plates, side plates, restraint straps, etc.) and then assembled into the power-consuming device.

[0091] Please see Figure 3 , Figure 3 This is an exploded view of a battery cell 10 provided in some embodiments of this application. The battery cell 10 is the smallest unit for storing and outputting electrical energy. The battery cell 10 includes components such as a housing 11, an electrode assembly 12, an insulator 13, electrode terminals 14, an adapter 15, a pressure relief mechanism 16, and an electrolyte (not shown in the figure).

[0092] The outer casing 11 is a component that isolates the internal environment of the battery cell 10 from the external environment. The outer casing 11 may include a housing 111 and an end cap 112. The end cap 112 is a component that closes onto the opening of the housing 111 to isolate the internal environment of the battery cell 10 from the external environment. In some embodiments, the shape of the end cap 112 may be adapted to the shape of the housing 111 to fit the housing 111. In some embodiments, the end cap 112 may be made of a material with a certain degree of hardness and strength, so that the end cap 112 is not easily deformed under pressure or impact, enabling the battery cell 10 to have high structural strength and reliability. The material of the end cap 112 can be diverse, including copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0093] The housing 111 is a component used to cooperate with the end cap 112 to form the internal environment of the battery cell 10. The internal environment formed by the housing 111 and the end cap 112 can be used to accommodate components such as the electrode assembly 12, the insulating component 13, and the electrolyte. In some embodiments, the housing 111 and the end cap 112 can be independent components, with an opening provided on the housing 111. The end cap 112 closes the opening to form the internal environment of the battery cell 10. In some embodiments, the end cap 112 and the housing 111 can also be integrated. Specifically, the end cap 112 and the housing 111 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 111, the end cap 112 closes the housing 111. The housing 111 can be of various shapes and sizes, such as a cuboid, a cylinder, or a hexagonal prism. The shape of the housing 111 can be determined according to the shape and size of the electrode assembly 12. The shell 111 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0094] Electrode assembly 12 is the component in the battery cell 10 where the electrochemical reaction occurs. The housing 11 may include one or at least two electrode assemblies 12. Electrode assembly 12 includes a separator and two electrodes of opposite polarity, the separator separating the two electrodes. "Two electrodes of opposite polarity" means that one of the two electrodes is a positive electrode and the other is a negative electrode. The two electrodes and the separator are wound together to form a rolled electrode assembly 12. In electrode assembly 12, the portions of the two electrodes containing active material constitute the electrode body 121 of electrode assembly 12, and the portions of the two electrodes without active material each constitute a tab 122, which is the current transmission terminal of electrode assembly 12 for transmitting current. The tab 122 of the positive electrode is called positive tab 122a, and the tab 122 of the negative electrode is called negative tab 122b. The positive tab 122a and the negative tab 122b can be located together at one end of the electrode body 121 or at both ends of the electrode body 121 respectively.

[0095] The electrolyte is a liquid that wets the electrode assembly 12. The battery cell 10 primarily functions by the movement of active ions between the positive and negative electrode plates. When the battery cell 10 is charging, active ions are generated on the positive electrode plate. These active ions can penetrate the pores of the separator, move through the electrolyte to the negative electrode plate, and embed themselves in the negative electrode active material. Conversely, when the battery cell 10 discharges, the active ions embedded in the negative electrode active material are released. These released active ions can penetrate the pores of the separator, move through the electrolyte to the positive electrode plate, and embed themselves in the positive electrode active material. The active ions can be lithium ions, sodium ions, etc.

[0096] Electrode terminal 14 is a component electrically connected to electrode assembly 12 and used for outputting or inputting electrical energy. Electrode terminal 14 includes a positive electrode terminal 14a and a negative electrode terminal 14b. Positive electrode terminal 14a is electrically connected to the positive electrode tab 122a of electrode assembly 12. Negative electrode terminal 14b is electrically connected to the negative electrode tab 122b of electrode assembly 12. Electrode terminal 14 can be mounted on housing 11 and stably mounted in a position and state relative to housing 11. In some embodiments, electrode terminal 14 can be mounted on housing 11 by means of flange riveting.

[0097] The adapter 15 is a current collector electrically connected between the tab 122 of the electrode assembly 12 and the corresponding electrode terminal 14. The adapter 15 may also be called an adapter connector, current collector plate, or adapter piece, etc. The adapter 15 has conductive properties and is made of a conductive material. The material of the adapter 15 may include aluminum, aluminum alloy, copper, copper alloy, copper-aluminum alloy, etc. The adapter 15 includes a positive electrode adapter 15a and a negative electrode adapter 15b. The positive electrode tab 122a of the electrode assembly 12 can be electrically connected to the positive electrode terminal 14a through the positive electrode adapter 15a, and the negative electrode tab 122b of the electrode assembly 12 can be electrically connected to the negative electrode terminal 14b through the negative electrode adapter 15b to form a current loop. In some embodiments, the adapter 15 can be connected to the tab 122 of the electrode assembly 12 by welding, abutment, or other methods. The adapter 15 can be connected to the electrode terminal 14 by welding, abutment, or other methods. The shape of the adapter 15 can be varied, such as square, round, irregular shape, etc.

[0098] The insulating component 13 is a component with insulating properties. The insulating component 13 is disposed within the housing 11, particularly between the electrode assembly 12 and the wall portion of the housing 11 having electrode terminals 14 (e.g., end cap 112). Based on the electrical connection between the tabs 122 of the electrode assembly 12 and the corresponding electrode terminals 14, the insulating component 13 can be used to insulate and isolate the electrode assembly 12 and the wall portion of the housing 11 having electrode terminals 14, thereby reducing the risk of short circuits, current leakage, etc. Furthermore, the insulating component 13 can also be fixed to the wall portion of the housing 11 having electrode terminals 14 and abut against the electrode assembly 12 to fill the gap between the electrode assembly 12 and the wall portion of the housing 11, thus tightly fixing the electrode assembly 12. This prevents the electrode assembly 12 from moving or shaking relative to the battery cell 10 during use, helps maintain the structural integrity of the battery cell 10, and reduces the risk of the electrode assembly 12 loosening or deforming.

[0099] A pressure relief mechanism 16 is disposed on the housing 11. The pressure relief mechanism 16 can be used to release internal pressure when the internal pressure (or temperature) of the battery cell 10 reaches a threshold. In some cases, the pressure relief mechanism 16 may also be referred to as an explosion-proof valve. In some embodiments, the pressure relief mechanism 16 may be integrally formed with the wall portion of the housing 11 for which the pressure relief mechanism 16 is disposed (e.g., end cap 112, etc.) (i.e., a one-piece structure), for example, the pressure relief mechanism 16 may be a groove provided on the corresponding wall portion of the housing 11. In other embodiments, the pressure relief mechanism 16 may be separately formed and separately connected with the corresponding wall portion of the housing 11 (e.g., end cap 112, etc.) (i.e., a separate structure).

[0100] Please see Figure 3 , Figure 4 , Figure 5 Some embodiments of this application provide a battery cell 10, which includes at least one electrode assembly 12. The electrode assembly 12 includes a separator 123, two electrodes 124 of opposite polarity, and an insulating layer 125. The two electrodes 124 and the separator 123 are wound together, and the electrode assembly 12 has a bending region 126. At least a portion of the insulating layer 125 is disposed in the bending region 126 and between the electrodes 124 and the separator 123. Please refer to the following: Figure 6 , Figure 7 The insulating layer 125 includes a base layer 1251 and a protrusion 1252, with the protrusion 1252 disposed on one side of the base layer 1251 along its own thickness direction.

[0101] It should be noted that the electrode assembly 12 is the component in the battery cell 10 where the electrochemical reaction takes place. One or more electrode assemblies 12 may be disposed inside the battery cell 10.

[0102] The electrode assembly 12 includes a diaphragm 123 and two electrodes 124. The two electrodes 124 are arranged with opposite polarities; that is, one of the electrodes 124 is a positive electrode 124a, and the other is a negative electrode 124b. The diaphragm 123 is an insulating membrane used to separate the two electrodes 124 with opposite polarities. The diaphragm 123 has several pores that allow active ions to pass through freely. The diaphragm 123 can be made of materials such as PP (polypropylene) or PE (polyethylene).

[0103] A diaphragm 123 and two electrodes 124 are stacked and wound together to form a rolled electrode assembly 12. Before winding, two diaphragms 123 are provided: one diaphragm 123 is disposed between the positive electrode 124a and the negative electrode 124b, and the other diaphragm 123 is disposed on the side of the negative electrode 124b facing away from the positive electrode 124a, or on the side of the positive electrode 124a facing away from the negative electrode 124b. This arrangement allows for the stacking of the diaphragm 123 and the two electrodes 124, and ensures that the diaphragm 123 separates the positive electrode 124a and the negative electrode 124b, preventing direct contact between them and thus avoiding a short circuit.

[0104] The coiled electrode assembly 12 has a main body region 127 and a bending region 126. The main body region 127 is the relatively straight portion of the electrode assembly 12 located in the middle, and the bending region 126 is the bent portion of the electrode assembly 12 located at one end of the main body region 127. For ease of understanding, as follows... Figure 4 As shown, the portion of the electrode assembly 12 located between the first reference line L1 and the second reference line L2 is the main body region 127, the portion to the left of the first reference line L1 is the bending region 126, and the portion to the right of the second reference line L2 is the bending region 126.

[0105] It should also be noted that in the electrode assembly 12, an insulating layer 125 may be provided on one side of the bending region 126, or an insulating layer 125 may be provided on both sides of the bending region 126. One or more insulating layers 125 may be provided in the bending region 126 where the insulating layer 125 is provided. At least a portion of the insulating layer 125 is provided in the bending region 126; that is, the insulating layer 125 may be entirely provided in the bending region 126, or it may be partially provided in the bending region 126 and partially provided in the main body region 127. The insulating layer 125 is provided between the electrode 124 and the separator 123. The insulating layer 125 may be provided between the positive electrode 124a and the separator 123, or it may be provided between the negative electrode 124b and the separator 123.

[0106] In some cases, the insulating layer 125 can be pre-positioned at a predetermined position on the positive electrode 124a or negative electrode 124b before winding. This allows the insulating layer 125 to be held between the bent portion of the electrode 124 and the separator 123 when the positive electrode 124a, separator 123, and negative electrode 124b are wound. This makes it convenient and quick to insert the insulating layer 125, and the bent portion of the electrode 124 and the separator 123 together tightly hold the insulating layer 125, thereby stabilizing the position and state of the insulating layer 125.

[0107] It should also be noted that the insulating layer 125 includes a substrate layer 1251 and at least one protrusion 1252. The protrusion 1252 protrudes from the substrate layer 1251 on one side along the thickness direction z of the substrate layer 1251. That is, the protrusion 1252 can be disposed on the side of the substrate layer 1251 facing away from the electrode 124 (i.e., facing the separator 123), or it can be disposed on the side of the substrate layer 1251 facing the electrode 124 (i.e., facing away from the separator 123). The substrate layer 1251 is the basic structure of the insulating layer 125, which can provide support and buffering effects over a large area. The protrusion 1252 can increase the thickness of the insulating layer 125 and its corresponding area, thereby enhancing the mechanical strength of the insulating layer 125 in that area and improving the overall ability of the insulating layer 125 to withstand stress (such as bending stress, pressure, tension, etc.).

[0108] The protrusion 1252 and the base layer 1251 can be an integrally formed structure or a separate connected structure.

[0109] The insulating layer 125 is made of insulating material, the specific material of which can be flexibly set as needed, such as PET (Polyethylene Terephthalate) or PP (polypropylene). The material of the protrusion 1252 can be the same as or different from the material of the substrate layer 1251. In some embodiments, the insulating layer 125 can restrict the free penetration of active ions. In other embodiments, the insulating layer 125 can allow the free penetration of active ions.

[0110] The insulating layer 125 has electrolyte resistance properties, which prevents the insulating layer 125 from dissolving in the electrolyte.

[0111] The protrusion 1252 can be, but is not limited to, a strip structure, a block structure, a dot structure, etc. When the protrusion 1252 is a strip structure, the protrusion 1252 can be extended in a straight line or extended in a curve.

[0112] Wherein, the length direction x of the substrate layer 1251 corresponds to the extension direction of the electrode 124 or the separator 123 to which it is attached, and also corresponds to the winding direction of the electrode 124 or the separator 123 to which it is attached; the width direction y of the substrate layer 1251 is perpendicular to the length direction x of the substrate layer 1251, and also corresponds to the width direction of the electrode 124 or the separator 123 to which it is attached; the thickness direction z of the substrate layer 1251 is perpendicular to its length direction and width direction, and also corresponds to the thickness direction of the electrode 124 or the separator 123 to which it is attached.

[0113] In summary, the battery cell 10 provided in this application embodiment provides an insulating layer 125 between the bent portion of the electrode 124 (i.e., the portion of the electrode 124 corresponding to the bending area 126) and the separator 123, and the insulating layer 125 includes a substrate layer 1251 and protrusions 1252 protruding from the substrate layer 1251. During the winding and pre-pressing of the electrode assembly 12 (not limited to hot pressing or cold pressing) and during the use of the battery cell 10, the insulating layer 125 provides support and buffering effects for the bent portion of the electrode 124. In particular, the substrate layer 1251 provides support and buffering effects over a large area to help evenly distribute bending stress and reduce local stress concentration in the electrode 124. In particular, the protrusions 1252 further reinforce the substrate layer 1251 to enhance its resistance to bending stress and load-bearing capacity, thereby reducing the bending stress borne by the bent portion of the electrode 124. Based on the supporting and reinforcing effect of the insulating layer 125, the risk of cracking and active material shedding in the bent portion of the electrode 124 can be effectively reduced. This reduces the risk of reduced active material content in the bent portion of the electrode 124 during the winding and pre-pressing of the electrode assembly 12 and during the use of the battery cell 10. This also reduces the risk of metal precipitation in the bent portion of the electrode 124 due to reduced active material during the use of the battery cell 10, alleviates metal precipitation in the bending region 126, reduces dendrite growth rate, and improves the reliability and service life of the battery cell 10. Furthermore, it reduces the risk of reduced energy density due to reduced active material, and maintains the energy density and electrochemical performance of the battery cell 10.

[0114] Based on the supporting and reinforcing effect of the insulating layer 125, the risk of burrs and other phenomena in the bent portion of the electrode 124 can be effectively reduced. Moreover, even if burrs are generated in the bent portion of the electrode 124, the insulating layer 125 can block the burrs to effectively prevent them from piercing the separator 123, thereby reducing the risk of internal short circuit in the battery cell 10 and improving the reliability and service life of the battery cell 10.

[0115] Furthermore, during the winding and pre-pressing of the electrode assembly 12, the insulating layer 125 can also, based on the substrate layer 1251 and the protrusion 1252, cause the bent portion of the electrode 124 to be tightly compacted and reduce the material gap, thereby improving the compaction of the electrode 124 (i.e., the density after compaction), which is beneficial to improving the energy density and electrochemical performance of the battery cell 10.

[0116] Please see Figure 5 , Figure 6 , Figure 7 , Figure 8In some embodiments of this application, the substrate layer 1251 has a middle portion 12511, which is located in the middle of the bending region 126 along the winding direction b, and the protrusion 1252 is disposed away from the middle portion 12511.

[0117] It should be noted that the substrate layer 1251 has a middle part 12511, which is located in the middle of the bending area 126 along the winding direction b. That is, the middle part 12511 is the middle folded area of ​​the substrate layer 1251, and will bear the main bending effect during the winding and pre-pressing process of the electrode assembly 12.

[0118] The protrusion 1252 is disposed away from the middle portion 12511, that is, the protrusion 1252 is disposed in an area other than the middle portion 12511, and is not disposed on the middle portion 12511. For example, along the winding direction b, the protrusion 1252 may be disposed on the side of the middle portion 12511. When there are multiple protrusions 1252, the multiple protrusions 1252 may be uniformly disposed on one side of the middle portion 12511, or they may be disposed on opposite sides of the middle portion 12511.

[0119] By adopting the above solution, the rigid support of the protrusion 1252 on the intermediate portion 12511 can be reduced, allowing the intermediate portion 12511 to have better flexibility and enabling it to bend freely and smoothly. This reduces the bending resistance of the intermediate portion 12511. Based on this, during the winding and pre-pressing of the electrode assembly 12, the insulating layer 125 can bend smoothly along with the electrode 124 and the diaphragm 123 via the intermediate portion 12511, and share the bending stress of the area of ​​the electrode 124 corresponding to the intermediate portion 12511. Furthermore, the protrusion 1252 can provide additional support and buffering in areas other than the intermediate portion 12511 to disperse bending stress and reduce stress concentration in the intermediate portion 12511. This reduces the risk of cracking, loss of active material, and burr formation in the bent portion of the electrode 124, and especially reduces the risk of cracking, loss of active material, and burr formation in the area corresponding to the middle portion 12511 of the electrode 124.

[0120] Please see Figure 5 , Figure 6 , Figure 7 , Figure 8 In some embodiments of this application, the insulating layer 125 is provided with a plurality of protrusions 1252, which are disposed on opposite sides of the middle portion 12511 along the winding direction b.

[0121] It should be noted that the insulating layer 125 contains multiple protrusions 1252. Along the winding direction b (i.e., along the length direction x of the substrate layer 1251), some protrusions 1252 are located on one side of the intermediate portion 12511, and other protrusions 1252 are located on the other side of the intermediate portion 12511. The number of protrusions 1252 in both portions can be the same or different. The protrusions 1252 can be designed in the same way or differently in terms of shape, size, and extension direction.

[0122] By adopting the above scheme, the insulating layer 125 can provide support and buffering on both sides of the middle portion 12511 through multiple protrusions 1252, and distribute and disperse bending stress relatively evenly on both sides of the middle portion 12511. This can relatively evenly optimize the resistance and load-bearing capacity of each region of the insulating layer 125 to bending stress, thereby enabling the electrode assembly 12 to be wound and pre-pressed during the winding and pre-pressing process, as well as during the battery cell 10 (e.g., Figure 3 (As shown) During use, the bending stress on each area of ​​the bent portion of the electrode 124 is reduced relatively evenly, the stress concentration in the bent portion of the electrode 124 is reduced, and the risk of cracking, loss of active material, and burr formation in the bent portion of the electrode 124 is reduced.

[0123] Of course, in other embodiments, the insulating layer 125 may be provided with a protrusion 1252. In other embodiments, all protrusions 1252 of the insulating layer 125 may be uniformly provided on one side of the middle portion 12511.

[0124] Please see Figure 5 , Figure 6 , Figure 7 In some embodiments of this application, along the thickness direction a of the electrode assembly 12, the projections of all protrusions 1252 of the same insulating layer 125 do not overlap at all.

[0125] It should be noted that this embodiment applies to the case where "the insulating layer 125 has multiple protrusions 1252" or "the insulating layer 125 has one protrusion 1252".

[0126] Along the thickness direction a of the electrode assembly 12, the projections of all the protrusions 1252 of the same insulating layer 125 do not overlap (i.e., the projections of any two protrusions 1252 do not intersect), but are staggered.

[0127] For example, such as Figure 5 , Figure 6 , Figure 7As shown, in some embodiments where "the insulating layer 125 is provided with multiple protrusions 1252", the substrate layer 1251 has a middle portion 12511, and the insulating layer 125 is provided with multiple protrusions 1252. Some of the protrusions 1252 are first protrusions 1252a and are located on one side of the middle portion 12511, and other protrusions 1252 are second protrusions 1252b and are located on the other side of the middle portion 12511. In the unfolded state (i.e., the flat state) of the insulating layer 125, the mirror projection of the second protrusion 1252b about the middle portion 12511 is offset from that of the first protrusion 1252a, so that in the bending area 126 of the formed electrode assembly 12, the projection of the second protrusion 1252b along the thickness direction a of the electrode assembly 12 does not overlap with the projection of the first protrusion 1252a along the thickness direction a of the electrode assembly 12.

[0128] For example, in some embodiments, the substrate layer 1251 has a middle portion 12511, and the insulating layer 125 is provided with one or more protrusions 1252, all of which are uniformly provided on one side of the middle portion 12511, so that in the bending area 126 of the formed electrode assembly 12, the projections of all protrusions 1252 along the thickness direction a of the electrode assembly 12 do not overlap at all.

[0129] By adopting the above scheme, by ensuring that the projections of all protrusions 1252 of the same insulating layer 125 along the thickness direction a of the electrode assembly 12 do not overlap, it is possible that in the tightly wound electrode assembly 12, on any reference line "passing through the protrusions 1252" and "parallel to the thickness direction a of the electrode assembly 12", the "chord length of the electrode 124 located on the outer side of the insulating layer 125" of two adjacent electrode pieces 124 is increased by a length L0 compared to the "chord length of the electrode 124 located on the inner side of the insulating layer 125" of two adjacent electrode pieces 124. L0 is the sum of the thickness d2 of the two base layers 1251 and the thickness d1 of the protrusion 1252. When the projections of the protrusions 1252 of the same insulating layer 125 overlap along the thickness direction a of the electrode assembly 12, the aforementioned L0 is the sum of the thickness d2 of the two base layers 1251 and the thickness d1 of the two protrusions 1252. Therefore, based on the configuration of this embodiment, the increase in the radius of curvature of the electrode 124 located on the outer side of the insulating layer 125 compared to the radius of curvature of the electrode 124 located on the inner side of the insulating layer 125 among two adjacent electrode sheets 124 is smaller. This results in a smaller increase in the average gap between the bent portions of two adjacent electrode sheets 124, thereby reducing the risk of a large increase in the active ion transport distance due to a large increase in the average gap between the bent portions of two adjacent electrode sheets 124. This also reduces the risk of exacerbating metal precipitation due to a large increase in the active ion transport distance, thus mitigating metal precipitation in the bent region 126, reducing dendrite growth rate, and improving the efficiency of the battery cell 10 (e.g., ...). Figure 3 (As shown) Reliability and service life.

[0130] Please see Figure 5 , Figure 6 In some embodiments of this application, the protrusion 1252 is a strip-shaped structure.

[0131] It should be noted that the protrusion 1252 is a strip-shaped structure, meaning that the protrusion 1252 extends in a strip-like manner. In the unfolded state of the insulating layer 125, the protrusion 1252 can extend in a straight line or in a curved line. When the protrusion 1252 extends in a straight line, its extension direction can be parallel to the length direction x of the substrate layer 1251 (e.g., ...). Figure 9 , Figure 10 As shown), they can also intersect (e.g., perpendicular to) the length direction x of the substrate layer 1251 (e.g., as shown). Figure 6 , Figure 8 (As shown).

[0132] By adopting the above scheme, and making the protrusion 1252 a strip structure, it is convenient for the protrusion 1252 to provide continuous support and buffering effect along its own extension direction. This facilitates the continuous and uniform distribution of bending stress along its extension direction, reducing local stress concentration. This enhances the overall resistance and load-bearing capacity of the insulating layer 125 to bending stress, reduces the bending stress borne by the bent portion of the electrode 124, and lowers the risk of cracking, active material shedding, and burr formation in the bent portion of the electrode 124. Furthermore, during the winding and pre-pressing of the electrode assembly 12, the strip-shaped protrusion 1252 can form a uniform contact pressure between the electrode 124 and the separator 123. This helps to relatively uniformly and tightly compact the components of the bent portion of the electrode 124 and reduce material gaps, thus improving the compaction of the electrode 124 and increasing the efficiency of the battery cell 10 (e.g., ...). Figure 3 The energy density and electrochemical performance are shown in the figure.

[0133] Of course, in other embodiments, the protrusion 1252 may be, but is not limited to, a block structure, a dot structure, etc.

[0134] Please see Figure 5 , Figure 9 , Figure 10 In some embodiments of this application, the extension direction of the protrusion 1252 is parallel to the length direction x of the substrate layer 1251.

[0135] It should be noted that the length direction x of the substrate layer 1251 corresponds to the extension direction of the electrode 124 or separator 123 to which it is attached, and also corresponds to the winding direction of the electrode 124 or separator 123 to which it is attached. The width direction y of the substrate layer 1251 is perpendicular to the length direction x of the substrate layer 1251, and also corresponds to the width direction of the electrode 124 or separator 123 to which it is attached.

[0136] In the unfolded state of the insulating layer 125, the protrusion 1252 is a strip structure, the protrusion 1252 extends in a straight line, and the extension direction of the protrusion 1252 is parallel to the length direction x of the substrate layer 1251.

[0137] By adopting the above scheme, by making the extension direction of the protrusion 1252 parallel to the length direction x of the substrate layer 1251, the extension direction of the protrusion 1252 can be made to conform to the extension direction b of the electrode sheet 124 or separator 123 attached to the substrate layer 1251. This allows the protrusion 1252 to have a longer extension length, which facilitates the alternating arrangement of a large number of protrusions 1252 in the width direction y of the substrate layer 1251. Based on this, during the winding and pre-pressing of the electrode assembly 12 and in the battery cell 10 (e.g., Figure 3As shown, during use, the protrusion 1252 can provide continuous and reliable support and buffering along the extension direction and winding direction b of the electrode 124, effectively bearing bending stress and distributing it more evenly. This enhances the overall resistance and load-bearing capacity of the insulating layer 125 to bending stress, reduces the bending stress borne by the bent portion of the electrode 124, and lowers the risk of cracking, active material shedding, and burr formation in the bent portion of the electrode 124. This embodiment is particularly suitable for situations where the substrate layer 1251 is relatively long, fully utilizing the extension length of the protrusion 1252 to better bear bending stress.

[0138] Please see Figure 5 , Figure 6 , Figure 8 In some embodiments of this application, the extension direction of the protrusion 1252 is perpendicular to the length direction x of the substrate layer 1251.

[0139] It should be noted that the length direction x of the substrate layer 1251 corresponds to the extension direction of the electrode 124 or separator 123 to which it is attached, and also corresponds to the winding direction of the electrode 124 or separator 123 to which it is attached. The width direction y of the substrate layer 1251 is perpendicular to the length direction x of the substrate layer 1251, and also corresponds to the width direction of the electrode 124 or separator 123 to which it is attached.

[0140] In the unfolded state of the insulating layer 125, the protrusion 1252 is a strip structure, the protrusion 1252 extends in a straight line, and the extension direction of the protrusion 1252 is perpendicular to the length direction x of the substrate layer 1251.

[0141] By adopting the above scheme, by making the extension direction of the protrusion 1252 perpendicular to the length direction x of the substrate layer 1251, the extension direction of the protrusion 1252 can be made perpendicular to the extension direction b of the electrode 124 or separator 123 attached to the substrate layer 1251, and in accordance with the width direction y of the substrate layer 1251 and the width direction of the electrode 124, it is convenient to alternately arrange a small number of protrusions 1252 in a more concentrated manner along the length direction x of the substrate layer 1251. Based on this, during the winding and pre-pressing of the electrode assembly 12 and in the battery cell 10 (e.g. Figure 3As shown, during use, the protrusions 1252 can provide strong local support and buffering in the bending area 126 along the width direction of the electrode 124. This focuses on bearing the bending stress in the bending area 126, reducing stress concentration, thereby enhancing the overall resistance and load-bearing capacity of the insulation layer 125 to bending stress. It also helps reduce the bending stress borne by the bent portion of the electrode 124, reducing the risk of cracking, active material shedding, and burr formation in the bent portion of the electrode 124. This embodiment is particularly suitable for situations where the substrate layer 1251 is relatively short, allowing the protrusions 1252 to be concentrated within the limited length of the substrate layer 1251, providing effective local support and better bearing the bending stress.

[0142] Of course, in other embodiments, the extending direction of the protrusion 1252 may intersect with but not be perpendicular to the length direction x of the substrate layer 1251. In other embodiments, the protrusion 1252 may be provided in a curved manner.

[0143] Please see Figure 5 , Figure 6 , Figure 9 In some embodiments of this application, the insulating layer 125 is provided with a plurality of protrusions 1252, which are arranged in parallel at intervals.

[0144] It should be noted that, based on the strip-shaped structure of the protrusion 1252, the insulating layer 125 is provided with multiple protrusions 1252, which are arranged parallel to each other and spaced apart from each other.

[0145] By adopting the above scheme, by setting multiple parallel and spaced protrusions 1252 on the insulating layer 125, the multiple parallel and spaced protrusions 1252 can work together in the bending area 126 to provide multi-area and large-scale support and buffering. They share the bending stress along the same extension direction and evenly distribute the bending stress, effectively reducing local stress concentration. This helps to evenly improve the resistance and load-bearing capacity of each area of ​​the insulating layer 125 to bending stress, reduces the bending stress borne by the bent part of the electrode 124, and reduces the risk of cracking, active material shedding, and burr formation in the bent part of the electrode 124.

[0146] Of course, in other embodiments, the insulating layer 125 may be provided with a protrusion 1252. In other embodiments, the plurality of protrusions 1252 of the insulating layer 125 may be flexibly arranged as needed.

[0147] Please see Figure 5 , Figure 7 , Figure 8 , Figure 10In some embodiments of this application, the substrate layer 1251 restricts the free penetration of active ions, and the substrate layer 1251 has a hollow structure 12513 through it along its thickness direction. The hollow structure 12513 is disposed along the thickness direction z of the substrate layer 1251 to avoid the protrusion 1252.

[0148] It should be noted that the substrate layer 1251 restricts the free penetration of active ions, that is, the substrate layer 1251 is made of a material that cannot conduct ions, such as, but not limited to, PET (Polyethylene Terephthalate).

[0149] Because the substrate layer 1251 restricts the free penetration of active ions, it hinders the transport of active ions. Consequently, the active material in the portion of the electrode 124 corresponding to the substrate layer 1251 cannot function properly, resulting in the sacrifice and waste of active material and affecting the utilization rate of active material and the battery cell 10 (e.g., Figure 3 The capacity and energy density of the battery cell 10 are shown in the figure. To address this issue, the substrate layer 1251 is provided with a hollow structure 12513. The hollow structure 12513 penetrates the substrate layer 1251 along the thickness direction z. The hollow structure 12513 can form a transport channel for electrolyte, active ions, electrons, etc., allowing active ions to penetrate freely. This allows the active material in the part of the electrode 124 corresponding to the hollow structure 12513 to function properly, reducing the sacrifice and waste of active material, and improving the utilization rate of active material and the capacity and energy density of the battery cell 10.

[0150] The hollow structure 12513 can be a hole structure, a groove structure, etc. The shape, size, and quantity of the hollow structure 12513 can be flexibly set as needed.

[0151] In this case, along the thickness direction z of the substrate layer 1251, the hollow structure 12513 is set to avoid the protrusion 1252 in order to maintain the structural integrity of the protrusion 1252 and thus maintain the effectiveness of the protrusion 1252.

[0152] By adopting the above scheme, under the condition that the substrate layer 1251 restricts the free penetration of active ions, by making the substrate layer 1251 have a through-hole structure 12513 through its thickness direction, it is convenient to form a transport channel for electrolyte, active ions, electrons, etc. through the through-hole structure 12513, so as to allow active ions to penetrate freely and improve ion transport efficiency. Based on this, the active material of the part of the electrode 124 corresponding to the through-hole structure 12513 can play a normal role and participate in the electrochemical reaction normally. This reduces the obstruction of the insulating layer 125 to the active material, reduces the sacrifice and waste of active material, improves the utilization rate of active material, and improves the capacity, energy density and electrochemical performance of the battery cell 10. Furthermore, by setting the hollow structure 12513 along the thickness direction z of the substrate layer 1251 to avoid the protrusion 1252, the structural integrity of the protrusion 1252 is maintained, so that the protrusion 1252 can normally play a reinforcing role on the substrate layer 1251, effectively enhancing the bending stress resistance and load-bearing capacity of the substrate layer 1251, and effectively reducing the stress concentration of the bent part of the electrode 124.

[0153] Please see Figure 5 , Figure 8 , Figure 10 In some embodiments of this application, the substrate layer 1251 includes a border portion 12512 and a middle portion 12511. The middle portion 12511 is located within the enclosed area of ​​the border portion 12512 and is located in the middle of the bending area 126 along the winding direction b. The hollow structure 12513 is provided to avoid the border portion 12512 and the middle portion 12511.

[0154] It should be noted that the substrate layer 1251 has a border portion 12512, which is the periphery of the substrate layer 1251, enclosing and forming a support frame for the substrate layer 1251, providing structural support and mechanical strength for the entire substrate layer 1251. The border portion 12512 is a closed ring, and its shape can be, but is not limited to, polygonal (e.g., rectangular), circular, etc.

[0155] The substrate layer 1251 has a middle portion 12511, which is located in the middle of the bending area 126 along the winding direction b. That is, the middle portion 12511 is the middle folded area of ​​the substrate layer 1251, and will bear the main bending effect during the winding and pre-pressing process of the electrode assembly 12.

[0156] The hollow structure 12513 is provided to avoid the border portion 12512 and the middle portion 12511, that is, the hollow structure 12513 is provided in the area of ​​the base layer 1251 other than the border portion 12512 and the middle portion 12511.

[0157] By adopting the above scheme, based on the formation of a transport channel for electrolyte, active ions, electrons, etc. through the hollow structure 12513, and by setting the hollow structure 12513 to avoid the border portion 12512 and the middle portion 12511, the structural integrity of the key support areas (i.e., the border portion 12512 and the middle portion 12511) of the substrate layer 1251 can be maintained. Therefore, it is convenient to provide structural support and mechanical strength to the entire substrate layer 1251 through the complete border portion 12512, and convenient to provide structural support and mechanical strength to the entire substrate layer 1251 through the complete middle portion 12512. The 12511 maintains the strength and flexibility of the central region of the substrate layer 1251, enabling the frame portion 12512 and the middle portion 12511 to jointly form a high-strength support frame for the substrate layer 1251. This allows the substrate layer 1251 to bend freely and flexibly during winding, pre-pressing, and use, effectively resisting and dispersing bending stress. It also reduces stress concentration at the bent portions of the electrode 124, lowering the risk of cracking, active material shedding, and burr formation at the bent portions of the electrode 124. Furthermore, maintaining the structural integrity of the frame portion 12512 facilitates the thorough and reliable installation and fixation of the insulating layer 125 via the frame portion 12512 in subsequent embodiments.

[0158] Please see Figure 3 , Figure 5 , Figure 6 In some embodiments of this application, the substrate layer 1251 allows active ions to penetrate freely.

[0159] It should be noted that the substrate layer 1251 allows active ions to pass through freely. That is, the substrate layer 1251 is made of a material capable of conducting ions, for example, it can be made of the same material as the diaphragm 123, such as PP (polypropylene), to allow active ions to pass through freely.

[0160] By adopting the above scheme, and by allowing active ions to freely penetrate the substrate layer 1251, the substrate layer 1251 itself possesses active ion transport channels, enabling active ions to freely penetrate. Based on this, the active material corresponding to the portion of the electrode 124 in the substrate layer 1251 can function normally and participate in electrochemical reactions, thereby reducing the obstruction of the insulating layer 125 to the active material, reducing the sacrifice and waste of active material, improving the utilization rate of active material, and enhancing the capacity, energy density, and electrochemical performance of the battery cell 10. Furthermore, the substrate layer 1251 does not require the inclusion of a hollow structure 12513 (e.g., Figure 8As shown, the substrate layer 1251 provides a transport channel for active ions. Based on this, the structure of the substrate layer 1251 can be simplified, the processing difficulty can be reduced, the processing steps can be reduced, and the processing and forming of the substrate layer 1251 and the insulating layer 125 can be facilitated. It can also improve the structural integrity, overall integrity and mechanical properties of the substrate layer 1251, so that the substrate layer 1251 can better resist and disperse bending stress during winding, pre-pressing and use. It can reduce the stress concentration of the bent part of the electrode 124, and reduce the risk of cracking, active material shedding and burr generation in the bent part of the electrode 124.

[0161] Please see Figure 5 , Figure 7 , Figure 8 In some embodiments of this application, the electrode assembly 12 includes an insulating adhesive layer 128. The side of the substrate layer 1251 facing away from the protrusion 1252 is bonded to the electrode 124 or the diaphragm 123 by the insulating adhesive layer 128. The insulating adhesive layer 128 is disposed along the thickness direction z of the substrate layer 1251, avoiding the hollow structure 12513.

[0162] It should be noted that this embodiment is mainly applicable to embodiments related to "the substrate layer 1251 restricts the free penetration of active ions, the substrate layer 1251 has a hollow structure 12513 through it along its thickness direction, and the hollow structure 12513 is set along the thickness direction z of the substrate layer 1251 to avoid the protrusion 1252".

[0163] It should also be noted that an insulating adhesive layer 128 is provided on the side of the substrate layer 1251 facing away from the protrusion 1252. The insulating adhesive layer 128 is adhesive, and the side of the substrate layer 1251 facing away from the protrusion 1252 can be bonded to the electrode 124 or the diaphragm 123 through the insulating adhesive layer 128, and thus installed and fixed relative to the electrode 124 or the diaphragm 123.

[0164] The insulating adhesive layer 128 has electrolyte resistance properties. In the battery cell 10 (e.g.) Figure 3 As shown, the insulating adhesive layer 128 does not dissolve in the electrolyte, the insulating adhesive layer 128 can exist permanently, and the insulating adhesive layer 128 can permanently and reliably bond and fix the insulating layer 125 to the electrode 124 or the diaphragm 123.

[0165] The insulating adhesive layer 128 has insulating properties, and the insulating adhesive layer 128 may be, but is not limited to, a hot melt adhesive.

[0166] In the thickness direction z of the substrate layer 1251, the insulating adhesive layer 128 is positioned to avoid the hollow structure 12513, so that the insulating adhesive layer 128 does not block the transmission channels of electrolyte, active ions, electrons, etc. formed by the hollow structure 12513.

[0167] By adopting the above solution, the side of the substrate layer 1251 facing away from the protrusion 1252 can be bonded and fixed to the electrode 124 or the diaphragm 123 through the insulating adhesive layer 128, so as to conveniently and quickly realize the installation and fixation of the insulating layer 125. This can conveniently, quickly and reliably stabilize the position and state of the insulating layer 125 between the electrode 124 and the diaphragm 123, enhance the overall structural stability of the electrode assembly 12, and enable the insulating layer 125 to be permanently and reliably stable between the electrode 124 and the diaphragm 123. It can also better resist and disperse bending stress during winding, pre-pressing and use. Furthermore, based on the perforated structure 12513 on the substrate layer 1251, the insulating adhesive layer 128 can be positioned along the thickness direction z of the substrate layer 1251 to avoid the perforated structure 12513. This ensures that the insulating adhesive layer 128 does not block or obstruct the transmission channel formed by the perforated structure 12513, thereby reducing the impact of the insulating adhesive layer 128 on the charging and discharging process of the electrode assembly 12 and the battery cell 10. This allows the perforated structure 12513 to function normally as a transmission channel, allowing electrolyte, active ions, and electrons to freely penetrate. It also allows the active material in the portion of the electrode 124 corresponding to the perforated structure 12513 to function normally and participate in the electrochemical reaction. This improves the utilization rate of active material and the active ion transport rate, thereby enhancing the capacity, energy density, and electrochemical performance of the battery cell 10.

[0168] Please see Figure 5 , Figure 6 , Figure 7 In some embodiments of this application, the electrode assembly 12 includes an insulating adhesive layer 128. The side of the substrate layer 1251 facing away from the protrusion 1252 is bonded to the electrode 124 or the diaphragm 123 by the insulating adhesive layer 128. Along the thickness direction z of the substrate layer 1251, the projected area of ​​the insulating adhesive layer 128 is smaller than the projected area of ​​the substrate layer 1251.

[0169] It should be noted that this embodiment is mainly applicable to embodiments related to "substrate layer 1251 allowing active ions to freely penetrate".

[0170] It should also be noted that an insulating adhesive layer 128 is provided on the side of the substrate layer 1251 facing away from the protrusion 1252. The insulating adhesive layer 128 is adhesive, and the side of the substrate layer 1251 facing away from the protrusion 1252 can be bonded to the electrode 124 or the diaphragm 123 through the insulating adhesive layer 128, and thus installed and fixed relative to the electrode 124 or the diaphragm 123.

[0171] The insulating adhesive layer 128 has electrolyte resistance properties. In the battery cell 10 (e.g.) Figure 3As shown, the insulating adhesive layer 128 does not dissolve in the electrolyte, the insulating adhesive layer 128 can exist permanently, and the insulating adhesive layer 128 can permanently and reliably bond and fix the insulating layer 125 to the electrode 124 or the diaphragm 123.

[0172] The insulating adhesive layer 128 has insulating properties, and the insulating adhesive layer 128 may be, but is not limited to, a hot melt adhesive.

[0173] In the thickness direction z of the substrate layer 1251, the projected area of ​​the insulating adhesive layer 128 is smaller than the projected area of ​​the substrate layer 1251, meaning that the insulating adhesive layer 128 is disposed in a portion of the substrate layer 1251. Based on this, the insulating adhesive layer 128 can reliably and permanently bond the substrate layer 1251 to the electrode 124 or the separator 123, while allowing transport channels to be preserved in areas of the substrate layer 1251 where the insulating adhesive layer 128 is not disposed, thus enabling active ions to freely penetrate.

[0174] By adopting the above solution, the side of the substrate layer 1251 facing away from the protrusion 1252 can be bonded and fixed to the electrode 124 or the diaphragm 123 through the insulating adhesive layer 128, so as to conveniently and quickly realize the installation and fixation of the insulating layer 125. This can conveniently, quickly and reliably stabilize the position and state of the insulating layer 125 between the electrode 124 and the diaphragm 123, enhance the overall structural stability of the electrode assembly 12, and enable the insulating layer 125 to be permanently and reliably stable between the electrode 124 and the diaphragm 123. It can also better resist and disperse bending stress during winding, pre-pressing and use. Furthermore, while allowing active ions to freely penetrate the substrate layer 1251, by making the projected area of ​​the insulating adhesive layer 128 smaller than that of the substrate layer 1251, the insulating adhesive layer 128 does not completely block or obstruct the transmission channels inherent in the substrate layer 1251. This reduces the impact of the insulating adhesive layer 128 on the charging and discharging process of the electrode assembly 12 and the battery cell 10. It also allows the areas of the substrate layer 1251 without the insulating adhesive layer 128 to normally provide transmission channels, enabling active ions to freely penetrate. This improves the utilization rate of active materials and the active ion transmission rate, thereby enhancing the capacity, energy density, and electrochemical performance of the battery cell 10.

[0175] In some embodiments, before the insulating layer 125 is bonded to the electrode 124 or the diaphragm 123 by the insulating adhesive layer 128, the insulating adhesive layer 128 can be pre-bonded to the side of the substrate layer 1251 facing away from the protrusion 1252, so that the insulating adhesive layer 128 and the insulating layer 125 are assembled into a laminated structure. Simultaneously, a peelable first release paper is pre-installed on the side of the insulating adhesive layer 128 facing away from the insulating layer 125. Based on this, the laminated structure, including the first release paper, the insulating adhesive layer 128, and the insulating layer 125, can be wound into a roll for easy production, storage, and transportation. In the roll, the first release paper is used to separate adjacent loops of the insulating adhesive layer 128 to prevent adjacent loops of the insulating adhesive layer 128 from sticking together. Therefore, when the insulating layer 125 is bonded to the electrode 124 or the diaphragm 123 through the insulating adhesive layer 128, the roll can be gradually unrolled and the first release paper can be gradually peeled off, so that the side of the insulating adhesive layer 128 away from the insulating layer 125 can be gradually bonded to the electrode 124 or the diaphragm 123, thereby making it convenient and quick to bond the insulating layer 125 to the electrode 124 or the diaphragm 123.

[0176] Please see Figure 11 In some embodiments of this application, the substrate layer 1251 is adhesive, and the side of the substrate layer 1251 facing away from the protrusion 1252 is bonded to the electrode 124 or the diaphragm 123.

[0177] It should be noted that this embodiment is applicable to related embodiments (such as) where "the substrate layer 1251 restricts the free penetration of active ions, and the substrate layer 1251 has a perforated structure 12513 extending along its thickness direction, and the perforated structure 12513 is arranged along the thickness direction z of the substrate layer 1251 to avoid the protrusion 1252". Figure 7 , Figure 8 , Figure 10 As shown, this also applies to embodiments related to "substrate layer 1251 allows active ions to penetrate freely".

[0178] It should also be noted that the substrate layer 1251 includes an adhesive, which is used to bond the other components of the substrate layer 1251 together. By increasing the amount of adhesive, the surface of the substrate layer 1251 can be made sufficiently viscous, so that the side of the substrate layer 1251 facing away from the protrusion 1252 can be bonded to the electrode 124 or the diaphragm 123 based on its own adhesiveness.

[0179] In some embodiments, the adhesion between the substrate layer 1251 and the electrode 124 or the diaphragm 123 can be enhanced by hot-melt bonding the substrate layer 1251 to the electrode 124 or the diaphragm 123.

[0180] By adopting the above scheme, the substrate layer 1251 can be bonded to the electrode 124 or diaphragm 123 conveniently, quickly, and reliably by increasing the content of the adhesive, so that the side facing away from the protrusion 1252 has sufficient adhesion. Based on this, the installation and fixation of the insulation layer 125 can be achieved conveniently and quickly, thereby stabilizing the position and state of the insulation layer 125 between the electrode 124 and the diaphragm 123 conveniently, quickly, and reliably. This can enhance the overall structural stability of the electrode assembly 12, enable the insulation layer 125 to be permanently and reliably stable between the electrode 124 and the diaphragm 123, and better resist and disperse bending stress during winding, pre-pressing, and use.

[0181] In some embodiments, before the insulating layer 125 is bonded to the electrode 124 or the separator 123 with an adhesive, a peelable second release paper can be pre-installed on the adhesive side of the substrate layer 1251. Based on this, the laminated structure, including the second release paper and the insulating layer 125, can be wound into a roll for easy production, storage, and transportation. In the roll, the second release paper separates adjacent loops of the insulating layer 125 to prevent them from sticking together. Therefore, when the insulating layer 125 is bonded to the electrode 124 or the separator 123 with an adhesive, the roll can be gradually unrolled, and the second release paper can be gradually peeled off, facilitating the gradual bonding of the insulating layer 125 to the electrode 124 or the separator 123.

[0182] Please see Figure 5 , Figure 12 In some embodiments of this application, the side of the substrate layer 1251 facing away from the protrusion 1252 is bonded to the electrode 124 or the diaphragm 123 by a solvent 129 soluble in the electrolyte.

[0183] It should be noted that this embodiment is applicable to related embodiments (such as) where "the substrate layer 1251 restricts the free penetration of active ions, and the substrate layer 1251 has a perforated structure 12513 extending along its thickness direction, and the perforated structure 12513 is arranged along the thickness direction z of the substrate layer 1251 to avoid the protrusion 1252". Figure 7 , Figure 8 , Figure 10 As shown, this also applies to embodiments related to "substrate layer 1251 allows active ions to penetrate freely".

[0184] It should also be noted that during the winding and pre-pressing of the electrode assembly 12, a solvent adhesive 129 is provided on the side of the substrate layer 1251 facing away from the protrusion 1252.

[0185] The solvent 129 can be applied to the entire area of ​​the side of the substrate layer 1251 facing away from the protrusion 1252. That is, in the thickness direction z of the substrate layer 1251, the projected area of ​​the solvent 129 is equal to the projected area of ​​the substrate layer 1251.

[0186] The solvent 129 can also be applied to a portion of the side of the substrate layer 1251 facing away from the protrusion 1252, meaning that the projected area of ​​the solvent 129 in the thickness direction z of the substrate layer 1251 is smaller than the projected area of ​​the insulating layer 125. In this scenario, the solvent 129 can be applied to any area of ​​the side of the substrate layer 1251 facing away from the protrusion 1252. In this scenario, the ratio of the projected area of ​​the solvent 129 to the projected area of ​​the insulating layer 125 in the thickness direction z of the substrate layer 1251 can be any value.

[0187] By adopting the above scheme, before the electrode assembly 12 is wound and formed, the side of the substrate layer 1251 facing away from the protrusion 1252 can be bonded to the electrode 124 or the diaphragm 123 at a preset position by means of solvent 129, so as to stabilize the preset position and preset state relative to the electrode 124 or the diaphragm 123. Based on this, during the winding and pre-pressing of the electrode assembly 12, the insulating layer 125 can be wound along with the electrode 124 or the diaphragm 123 in a stable position and state relative to the electrode 124 or the diaphragm 123, and wound to the bending area 126. This allows for convenient and quick installation and fixation of the insulating layer 125, and convenient, quick and reliable stabilization of the position and state of the insulating layer 125 between the electrode 124 and the diaphragm 123. This enhances the overall structural stability of the electrode assembly 12, and enables the insulating layer 125 to be permanently and reliably stable between the electrode 124 and the diaphragm 123. It also effectively resists and disperses bending stress during winding, pre-pressing and use.

[0188] It should be noted that the solvent 129 is readily soluble in the electrolyte. The electrode assembly 12 and the electrolyte are then incorporated into the battery cell 10 (e.g., Figure 3 When the electrolyte is filled with the substrate layer 1251 (as shown), the solvent 129 will dissolve at least a portion of it in the electrolyte to reduce or even eliminate the obstruction of the insulating layer 125. Therefore, in this embodiment, the electrolyte contains the solvent 129. The solvent 129 may be completely dissolved in the electrolyte, or it may be partially dissolved and partially remain between the substrate layer 1251 and the electrode 124 or separator 123. When the solvent 129 remains partially, it may slightly obstruct a portion of the insulating layer 125, but it will not significantly affect the charging and discharging process of the battery cell 10.

[0189] By adopting the above scheme, when the electrode assembly 12 and electrolyte are installed inside the battery cell 10, the solvent 129 can be at least partially dissolved in the electrolyte to reduce or even eliminate the obstruction of the insulating layer 125. This allows a transmission channel to be left between the insulating layer 125 and the electrode 124 or separator 123, allowing active ions to penetrate freely. This reduces the impact of the solvent 129 on the charging and discharging process of the electrode assembly 12 and the battery cell 10, improves the utilization rate of active materials and the active ion transport rate, and enhances the capacity, energy density and electrochemical performance of the battery cell 10.

[0190] For example, in some embodiments, the solvent 129 is a modified acrylic pressure-sensitive adhesive, and the electrolyte contains modified acrylic resin. By adopting the above solution, on the one hand, the solvent 129 can have the liquid viscous properties of a pressure-sensitive adhesive, thereby facilitating the convenient, quick, and reliable molding of the solvent 129 onto the side of the substrate layer 1251 opposite to the protrusion 1252 by coating. On the other hand, the solvent 129 can have the solid elastic properties of a pressure-sensitive adhesive, thereby facilitating the easy and reliable bonding of the solvent 129 to the electrode 124 or diaphragm 123 with only a small amount of pressure before the electrode assembly 12 is wound and molded, thereby conveniently and quickly achieving stable bonding of the insulating layer 125 to the electrode 124 or diaphragm 123 at a predetermined position. On the one hand, it allows the solvent 129 to have the easily degradable properties of modified acrylic resin, thereby facilitating the rapid and non-residual dissolution of the solvent 129 in the electrolyte when the electrode assembly 12 and the electrolyte are encapsulated inside the battery cell 10.

[0191] Please see Figure 13 In some embodiments of this application, the electrode assembly 12 includes a conductive adhesive layer 1210, and the side of the substrate layer 1251 facing away from the protrusion 1252 is bonded to the electrode 124 or the diaphragm 123 through the conductive adhesive layer 1210.

[0192] It should be noted that this embodiment is applicable to related embodiments (such as) where "the substrate layer 1251 restricts the free penetration of active ions, and the substrate layer 1251 has a perforated structure 12513 extending along its thickness direction, and the perforated structure 12513 is arranged along the thickness direction z of the substrate layer 1251 to avoid the protrusion 1252". Figure 7 , Figure 8 , Figure 10 As shown, this also applies to embodiments related to "substrate layer 1251 allows active ions to penetrate freely".

[0193] It should also be noted that a conductive adhesive layer 1210 is provided on the side of the substrate layer 1251 facing away from the protrusion 1252. The conductive adhesive layer 1210 is adhesive, and the side of the substrate layer 1251 facing away from the protrusion 1252 can be bonded to the electrode 124 or the diaphragm 123 through the conductive adhesive layer 1210, and thus installed and fixed relative to the electrode 124 or the diaphragm 123.

[0194] The conductive adhesive layer 1210 has electrolyte resistance properties. In the battery cell 10 (e.g.... Figure 3 As shown, the conductive adhesive layer 1210 does not dissolve in the electrolyte, the conductive adhesive layer 1210 can exist permanently, and the conductive adhesive layer 1210 can permanently and reliably bond and fix the insulating layer 125 to the electrode 124 or the diaphragm 123.

[0195] The conductive adhesive layer 1210 is conductive and provides a transport channel, allowing active ions to penetrate freely.

[0196] By adopting the above solution, based on the adhesive properties and electrolyte resistance of the conductive adhesive layer 1210, the side of the substrate layer 1251 facing away from the protrusion 1252 can be bonded and fixed to the electrode 124 or the diaphragm 123 through the conductive adhesive layer 1210. This allows for convenient and quick installation and fixation of the insulating layer 125, thereby stabilizing the position and state of the insulating layer 125 between the electrode 124 and the diaphragm 123 in a convenient, quick, and reliable manner. This enhances the overall structural stability of the electrode assembly 12, ensures that the insulating layer 125 can be permanently and reliably fixed between the electrode 124 and the diaphragm 123, and effectively resists and disperses bending stress during winding, pre-pressing, and use. Furthermore, based on the conductivity of the conductive adhesive layer 1210, the conductive adhesive layer 1210 itself also has a transport channel, which allows active ions to pass through freely. This reduces the impact of the conductive adhesive layer 1210 on the charging and discharging process of the electrode assembly 12 and the battery cell 10. It also facilitates the creation of a transport channel between the insulating layer 125 and the electrode 124 or the separator 123, thereby improving the utilization rate of active materials and the active ion transport rate, and enhancing the capacity, energy density and electrochemical performance of the battery cell 10.

[0197] Please see Figure 5 , Figure 6 , Figure 7 In some embodiments of this application, along the thickness direction z of the substrate layer 1251, the thickness d1 of the protrusion 1252 is 1 to 3 times the thickness d2 of the substrate layer 1251.

[0198] It should be noted that, along the thickness direction z of the substrate layer 1251, the thickness d1 of the protrusion 1252 is 1 to 3 times the thickness d2 of the substrate layer 1251. For example, the thickness d1 of the protrusion 1252 can be 1, 1.2, 1.5, 1.8, 2, 2.5, 3 times, etc., of the thickness d2 of the substrate layer 1251.

[0199] By adopting the above scheme, the thickness of the protrusion 1252 along the thickness direction z of the substrate layer 1251 can be made moderate, without being too large. Based on this, on the one hand, the protrusion 1252 can more effectively bear and disperse bending stress, thereby enhancing the overall resistance and load-bearing capacity of the insulating layer 125 to bending stress, reducing the bending stress borne by the bent portion of the electrode 124, and reducing the risk of cracking, active material shedding, and burr formation in the bent portion of the electrode 124. On the other hand, it can reduce the risk of a large average gap between the bent portions of adjacent electrodes 124 due to excessive thickness d1 of the protrusion 1252, reducing the risk of a large active ion transport distance due to a large average gap between the bent portions of adjacent electrodes 124, and reducing the risk of increased metal precipitation due to a large active ion transport distance. This can alleviate the metal precipitation phenomenon in the bending region 126, reduce the dendrite growth rate, and improve the efficiency of the battery cell 10 (e.g., Figure 3 (As shown) Reliability and service life.

[0200] Please see Figure 3 , Figure 4 , Figure 5 In some embodiments of this application, the insulating layer 125 is disposed on the convex side (outer side) or concave side (inner side) of the first to third turns of the electrode 124 from the inside out.

[0201] It should be noted that, from the inner ring to the outer ring of the electrode assembly 12, the first ring of electrode plates 124 includes the first ring of positive electrode plates 124a and the first ring of negative electrode plates 124b, which is the innermost ring of electrode plates 124; the second ring of electrode plates 124 includes the second ring of positive electrode plates 124a and the second ring of negative electrode plates 124b, which is the next innermost ring of electrode plates 124; and so on. Each ring of positive electrode plate 124a has two bent portions, and each ring of negative electrode plate 124b has two bent portions. In this embodiment, one or more insulating layers 125 can be provided. The insulating layers 125 are provided on the bent portions of the first to third rings of electrode plates 124 from the inside out. The insulating layers 125 can be provided on the convex side (outer side) or the concave side (inner side) of the electrode plates 124.

[0202] Because the radius of curvature of the innermost ring is smaller and the stress is greater, the risk of cracking, active material shedding, and burr formation in the bent portion of the innermost ring of electrode 124 is greater. Therefore, by adopting the above solution, by placing the insulating layer 125 on the convex or concave side of the first to third rings of electrode 124 from the inside out, the insulating layer 125 can mainly help the bent portion of the first to third rings of electrode 124 from the inside out to bear and disperse the bending stress, thereby mainly reducing the risk of cracking, active material shedding, and burr formation in the bent portion of the first to third rings of electrode 124 from the inside out.

[0203] Furthermore, since it can significantly reduce the risk of cracking and active material detachment in the bending portions of the first to third turns of the electrode 124 from the inside out, it can also significantly reduce the risk of reduced active material content in the bending portions of the first to third turns of the electrode 124 from the inside out. Therefore, during the use of the battery cell 10, it can significantly reduce the risk of metal precipitation intensified in the bending portions of the first to third turns of the electrode 124 from the inside out, effectively alleviate metal precipitation in the bending area 126, effectively reduce dendrite growth rate, and thus effectively improve the reliability and service life of the battery cell 10.

[0204] Of course, in other embodiments, the insulating layer 125 may be disposed on the convex or concave side of the electrode 124 in the fourth and outermost rings.

[0205] Please see Figure 3 , Figure 4 , Figure 5 , Figure 7 , Figure 8 Based on the above embodiments, this application provides a specific example of a battery cell 10. The battery cell 10 includes at least one electrode assembly 12, which includes a separator 123, two electrodes 124 with opposite polarities, an insulating layer 125, and an insulating adhesive layer 128. The two electrodes 124 and the separator 123 are wound together, and the electrode assembly 12 has a bending region 126.

[0206] At least a portion of the insulating layer 125 is disposed in the bending region 126, and between the electrode 124 and the separator 123, and is disposed on the convex or concave side of the electrode 124 in the first to third turns from the inside out. The insulating layer 125 includes a substrate layer 1251 and a plurality of protrusions 1252. Each protrusion 1252 is disposed on one side of the substrate layer 1251 along its own thickness direction, and the side of the substrate layer 1251 facing away from the protrusions 1252 is bonded to the electrode 124 or the separator 123 by an insulating adhesive layer 128. The protrusions 1252 are strip-shaped structures, and the extension direction of the protrusions 1252 is perpendicular to the length direction x of the substrate layer 1251. The protrusions 1252 are arranged in parallel at intervals. Along the thickness direction z of the substrate layer 1251, the thickness d1 of the protrusions 1252 is 1 to 3 times the thickness d2 of the substrate layer 1251. The substrate layer 1251 includes a border portion 12512 and a middle portion 12511. The middle portion 12511 is located within the enclosed area of ​​the border portion 12512 and is situated in the middle of the bending area 126 along the winding direction b. Protrusions 1252 are disposed away from the middle portion 12511, and along the winding direction b, each protrusion 1252 is located on opposite sides of the middle portion 12511. Along the thickness direction a of the electrode assembly 12, the projections of all protrusions 1252 on the same insulating layer 125 do not overlap.

[0207] The substrate layer 1251 restricts the free penetration of active ions. A perforated structure 12513 extends through the substrate layer 1251 along its thickness direction, avoiding the protrusion 1252. The perforated structure 12513 also avoids the border portion 12512 and the middle portion 12511. The insulating adhesive layer 128 is positioned along the thickness direction of the substrate layer 1251, avoiding the perforated structure 12513.

[0208] Based on the above configuration, the insulating layer 125 provides support and buffering for the bent portion of the electrode 124 during the winding and pre-pressing of the electrode assembly 12 and during the use of the battery cell 10; in particular, the substrate layer 1251 provides support and buffering over a large area to help evenly distribute bending stress and reduce local stress concentration in the electrode 124; in particular, the substrate layer 1251 is further reinforced by the protrusions 1252 to enhance its resistance to and load-bearing capacity against bending stress, thereby reducing the bending stress borne by the bent portion of the electrode 124. Based on the supporting and reinforcing effect of the insulating layer 125, the risk of cracking and active material shedding in the bent portion of the electrode 124 can be effectively reduced. This reduces the risk of reduced active material content in the bent portion of the electrode 124 during the winding and pre-pressing of the electrode assembly 12 and during the use of the battery cell 10. This also reduces the risk of metal precipitation in the bent portion of the electrode 124 due to reduced active material during the use of the battery cell 10, alleviates metal precipitation in the bending region 126, reduces dendrite growth rate, and improves the reliability and service life of the battery cell 10. Furthermore, it reduces the risk of reduced energy density due to reduced active material, and maintains the energy density and electrochemical performance of the battery cell 10.

[0209] Based on the supporting and reinforcing effect of the insulating layer 125, the risk of burrs and other phenomena in the bent portion of the electrode 124 can be effectively reduced. Moreover, even if burrs are generated in the bent portion of the electrode 124, the insulating layer 125 can block the burrs to effectively prevent them from piercing the separator 123, thereby reducing the risk of internal short circuit in the battery cell 10 and improving the reliability and service life of the battery cell 10.

[0210] Furthermore, during the winding and pre-pressing of the electrode assembly 12, the insulating layer 125 can also, based on the substrate layer 1251 and the protrusion 1252, cause the bent portion of the electrode 124 to be tightly compacted and reduce the material gap, thereby improving the compaction of the electrode 124 (i.e., the density after compaction), which is beneficial to improving the energy density and electrochemical performance of the battery cell 10.

[0211] Furthermore, during the use of the battery cell 10, the hollow structure 12513 facilitates the formation of transport channels for electrolyte, active ions, electrons, etc., allowing active ions to penetrate freely and improving ion transport efficiency. Based on this, the active material in the portion of the electrode 124 corresponding to the hollow structure 12513 can function normally and participate in electrochemical reactions normally. This reduces the obstruction of the insulating layer 125 and the insulating adhesive layer 128 to the active material, reduces the sacrifice and waste of active material, improves the utilization rate of active material, and enhances the capacity, energy density, and electrochemical performance of the battery cell 10. Furthermore, by setting the hollow structure 12513 along the thickness direction z of the substrate layer 1251 to avoid the protrusion 1252, the frame portion 12512, and the middle portion 12511, the structural integrity of the protrusion 1252, the frame portion 12512, and the middle portion 12511 is maintained. This allows the insulating layer 125 to better resist and disperse bending stress based on the protrusion 1252, the frame portion 12512, and the middle portion 12511, thereby reducing stress concentration in the bent portion of the electrode 124 and lowering the risk of cracking, active material shedding, and burr formation in the bent portion of the electrode 124. It also allows the insulating layer 125 to achieve thorough and reliable bonding and fixation to the electrode 124 or the diaphragm 123 based on the frame portion 12512 and the insulating adhesive layer 128 corresponding to the frame portion 12512.

[0212] Please see Figure 2 , Figure 3 Some embodiments of this application provide a battery device 1, which includes a battery cell 10 provided in the embodiments of this application.

[0213] By adopting the above solution, the battery device 1 can improve its charge and discharge performance, cycle performance, and reliability by applying the battery cell 10 provided in the embodiments of this application, and extend the service life of the battery device 1.

[0214] Please see Figure 1 , Figure 3 Some embodiments of this application provide an electrical device, which includes a battery device 1 provided in the embodiments of this application, or a battery cell 10 provided in the embodiments of this application.

[0215] By adopting the above solution, the electrical device can improve its performance, reliability, and service life by using the battery device 1 or battery cell 10 provided in the embodiments of this application.

[0216] The above are merely optional embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A battery cell, wherein, The battery cell includes at least one electrode assembly, which includes a separator, two electrodes of opposite polarity, and an insulating layer. The two electrodes and the diaphragm are wound together, and the electrode assembly has a bending area; At least a portion of the insulating layer is disposed in the bending region and between the electrode and the diaphragm; The insulating layer includes a base layer and a protrusion, wherein the protrusion is located on one side of the base layer along its own thickness direction.

2. The battery cell according to claim 1, wherein, The substrate layer has a middle portion located in the middle of the bending area along the winding direction, and the protrusion is disposed away from the middle portion.

3. The battery cell according to claim 2, wherein, The insulating layer is provided with a plurality of protrusions, which are located on opposite sides of the middle portion along the winding direction.

4. The battery cell according to any one of claims 1-3, wherein, Along the thickness direction of the electrode assembly, the projections of all the protrusions in the same insulating layer do not overlap at all.

5. The battery cell according to any one of claims 1-4, wherein, The protrusion has a strip-shaped structure.

6. The battery cell according to claim 5, wherein, The extension direction of the protrusion is parallel to the length direction of the substrate layer.

7. The battery cell according to claim 5, wherein, The extension direction of the protrusion is perpendicular to the length direction of the substrate layer.

8. The battery cell according to any one of claims 5-7, wherein, The insulating layer has a plurality of protrusions, which are arranged in parallel and spaced apart.

9. The battery cell according to any one of claims 1-8, wherein, The substrate layer restricts the free penetration of active ions, and the substrate layer has a perforated structure along its thickness direction, the perforated structure being arranged along the thickness direction of the substrate layer to avoid the protrusion.

10. The battery cell according to claim 9, wherein, The substrate layer includes a border portion and a middle portion. The middle portion is located within the enclosed area of ​​the border portion and is situated in the middle of the bending area along the winding direction. The hollow structure is provided to avoid the border portion and the middle portion.

11. The battery cell according to any one of claims 1-8, wherein, The matrix layer allows active ions to penetrate freely.

12. The battery cell according to claim 9 or 10, wherein, The electrode assembly includes an insulating adhesive layer. The side of the substrate layer facing away from the protrusion is bonded to the electrode or the diaphragm through the insulating adhesive layer. The insulating adhesive layer is disposed along the thickness direction of the substrate layer, avoiding the hollow structure.

13. The battery cell according to claim 11, wherein, The electrode assembly includes an insulating adhesive layer. The side of the substrate layer facing away from the protrusion is bonded to the electrode or the diaphragm through the insulating adhesive layer. Along the thickness direction of the substrate layer, the projected area of ​​the insulating adhesive layer is smaller than the projected area of ​​the substrate layer.

14. The battery cell according to any one of claims 1-11, wherein, The substrate layer is adhesive, and the side of the substrate layer opposite to the protrusion is bonded to the electrode or the diaphragm.

15. The battery cell according to any one of claims 1-11, wherein, The side of the substrate layer facing away from the protrusion is bonded to the electrode or the diaphragm by a solvent adhesive that is soluble in the electrolyte.

16. The battery cell according to claim 15, wherein, The electrolyte contains the solvent gel.

17. The battery cell according to any one of claims 1-11, wherein, The electrode assembly includes a conductive adhesive layer, and the side of the substrate layer facing away from the protrusion is bonded to the electrode or the diaphragm through the conductive adhesive layer.

18. The battery cell according to any one of claims 1-17, wherein, Along the thickness direction of the substrate layer, the thickness of the protrusion is 1 to 3 times the thickness of the substrate layer.

19. The battery cell according to any one of claims 1-18, wherein, The insulating layer is disposed on the convex or concave side of the electrode in the first to third turns from the inside out.

20. A battery device, wherein, The battery device comprises a battery cell as described in any one of claims 1-19.

21. An electrical appliance, wherein, The electrical device includes the battery device as described in claim 20, or the battery cell as described in any one of claims 1-19.

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